Autonomous Discovery of Tough Structures

TL;DR

This paper introduces a self-driving lab that uses machine learning to autonomously discover highly efficient energy-absorbing structures, significantly advancing design principles for protective systems across various applications.

Contribution

It demonstrates the first large-scale autonomous experimental platform that uncovers new design principles for energy-absorbing structures using over 25,000 experiments guided by machine learning.

Findings

Achieved record-high energy absorption efficiency.

Uncovered design principles for elastic and plastic materials.

Showed the effectiveness of autonomous experimentation in materials discovery.

Abstract

A key feature of mechanical structures ranging from crumple zones in cars to padding in packaging is their ability to provide protection by absorbing mechanical energy. Designing structures to efficiently meet these needs has profound implications on safety, weight, efficiency, and cost. Despite the wide varieties of systems that must be protected, a unifying design principle is that protective structures should exhibit a high energy-absorbing efficiency, or that they should absorb as much energy as possible without mechanical stresses rising to levels that damage the system. However, progress in increasing the efficiency of such structures has been slow due to the need to test using tedious and manual physical experiments. Here, we overcome this bottleneck through the use of a self-driving lab to perform >25,000 machine learning-guided experiments in a parameter space with at minimum trillions of possible designs. Through these experiments, we realized the highest mechanical energy absorbing efficiency recorded to date. Furthermore, these experiments uncover principles that can guide design for both elastic and plastic classes of materials by incorporating both geometry and material into a single model. This work shows the potential for sustained operation of self-driving labs with a strong human-machine collaboration.